System and method for atmospheric carbon sequestration

ABSTRACT

This invention relates to systems and methods for converting biomass into highly inert carbon. Specifically, some embodiments densify the carbon into anthracite-style carbon aggregations and store it in geologically stable underground deposits. The use of certain embodiments yield a net effect of removing atmospheric carbon via the process of photosynthesis and converting it into hard coal, which can be stored in underground beds that mimic existing coal deposits which are known to be stable for thousands of years.

REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/143,518 filed Jan. 9, 2009, the content of which is incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The present invention is directed towards carbon sequestration, and moreparticularly, some embodiments of the invention provide systems andmethods for converting biomass into highly inert carbon for long-termstorage.

DESCRIPTION OF THE RELATED ART

Global warning is one of the top issues of the early 21st century.Several billion tons of fossil fuels are burned worldwide each year. Thevast majority of the scientific community believes that about half thecarbon from the burning of fossil fuel remains in the atmosphere for atleast hundreds of years. Ice core samples indicate that the atmosphericCO₂ level has been relatively stable at 280 ppm for tens of thousands ofyears prior to the beginning of the industrial revolution in the early1800s. Atmospheric carbon in the form of CO₂ has increased 40 percent bythe early 21st century to 390 ppm due to the widespread use of fossilfuels. In the last few years, rapid increases in industrialization inthe developing world have compounded the rate of increase of fossil fuelusage. There is also some evidence that natural sinks for about half ofthe CO₂ that is emitted from fossil fuel are starting to saturate due tothe increasing CO₂ concentration or are losing their effectiveness dueto global temperature rise. Consequently, scientific projections offuture atmospheric CO₂ levels from just a decade ago substantiallyunderestimate the current rate of increase of atmospheric CO₂. Manyscientists are now concerned that the planet is close to a tipping pointbecause increased CO₂ emissions are producing thermal effects which arefeeding back on themselves and thus further increasing the rate ofglobal warming. Clearly, there is urgent need for technologies toreverse this trend, and specifically for technologies, which can reducethe concentration of atmospheric CO₂, i.e., atmospheric carbon.

Each year, about 100 billion tons of atmospheric carbon is absorbed byplants via the process of photosynthesis. However, each year, anapproximately equal amount of carbon is returned to the atmosphere bythe earth's biomass due to plant respiration, the decay of dead plantmatter, wildfires and human directed biomass burning, and otherprocesses. The photosynthesis absorption of carbon and subsequentbiomass release of that carbon remained in equilibrium for at least tensof thousands of years prior to the beginning of the industrialrevolution as witnessed by ice core samples which have entrappedatmospheric gasses which have been sampled at both northern polar andsouthern polar ice regions.

Prior to human intervention, a small percentage of plant growth was ingeographic regions, which, due to the local climate, topography andhydrology was prone to the development of peat bogs or other biomasspreservation mechanisms. Over geologic timescales, these bogs evolvewith changing climate and geology such that they become buried underlater stage sedimentation and develop through a well documented processof transitioning to lignite coal, then bituminous coal and then,ultimately, anthracite or hard coal. Such coal deposits are found allover the world and contain hundreds of billions of tons of carbon. Thecarbon concentration in bog peat is relatively low and then progressesto about 50% in wet lignite coal, then to the 70% range in bituminouscoal and, ultimately, can be as high as 99% in anthracite coal. Highpurity carbon, as is found in anthracite coal, is very chemically inertand is not attacked by acids, bases, biological activity or othermechanisms commonly found underground. In many areas, very ancientdeposits of coal, as witnessed by their embedded fossils, can be foundjust a few feet below ground level and are, thus, not attacked by normalenvironmental mechanisms for at least thousands of years. Over the lastfew hundred years, bog peat has been actively stripped as a convenientfuel source and has, thus, largely stopped the formation of new coaldeposits.

Currently, humanity is not removing any significant amount ofatmospheric carbon for long-term storage to offset the large amount ofcarbon dumped in the atmosphere by fossil fuel burning. In addition todumping carbon from fossil fuel burning, land development typicallyreleases, on an accelerated basis, carbon from decaying plant matterthat had been stored in equilibrium conditions via mature ecosystems. Asa result, over the past few years, several modern approaches to CO₂sequestration have been proposed to resolve the problem.

Under one proposal, liquefied CO₂) would be injected under high pressureinto deep underground structures. The current prototype for this is theuse of high pressure CO₂ in the recovery of extra oil from declining oilfields. This, however, is not a truly carbon sequestration processbecause it actually produces more fossil fuel. In addition, the effectsof massive amounts of deep CO₂ injection are unknown and may producehighly undesirable side effects. For example, CO₂ becomes a verypowerful supercritical solvent well below the pressures and temperaturesthat will be used in deep CO₂ injection. As a supercritical solvent, theCO₂ readily picks up active chemicals that can increase its ability todissolve substances. Accordingly, with its increased ability to dissolvesubstances, it is likely that supercritical CO₂ injection will notremain stable for geological period. Although similar proposals havebeen made for deep ocean CO₂ injection, the concern for stability over along period of time remains.

Other proposals involve reacting or absorbing CO₂ with other mineralssuch as calcium oxide. However, such a proposal requires huge quantitiesof suitable minerals to directly neutralize atmospheric CO₂. In the caseof calcium oxide, most of the world's calcium is already stored ascalcium carbonate, so it cannot be effectively repurposed for morecarbon storage.

In addition to CO₂ sequestration, some proposals aim to mitigate theproblems of the global warming with carbon neutral solutions. One suchpopular solution is the use of biofuels, which uses the carbon andhydrogen bond energy from the photosynthesis capture of carbon toproduce fuels that can be used as an alternative to fossil fuels.Although the burning of biofuels ultimately releases carbon back intothe atmosphere, the carbon released originates from the atmosphere andwas merely captured by the photosynthesis process. As such, the use ofbiofuels as fossil fuels is considered to be carbon neutral.

Other carbon neutral solutions include solar, wind and nuclear powerstations, which can be used directly for stationary power applicationsor can be used to charge batteries to power mobile transportapplications. These known solutions make no use of carbon at all.Unfortunately, none of the above-identified carbon neutral solutionsaddresses the CO₂ concentration that currently exists is in theatmosphere and the additional CO₂ that to be spewed into the atmosphereby the future use of fossil fuels.

SUMMARY OF THE INVENTION

The invention is directed toward systems and methods for producinghighly inert carbon via various pyrolysis products of biomass, in orderto address the atmospheric concentration of CO₂ and either reduce orbalance it against increased fossil fuel carbon emissions.

Some embodiments of the invention involve a method for carbonsequestration, comprising: providing biomass to a pyrolyzing system,wherein the pyrolyzing system generates biochar and filtrate carbon;collecting the biochar and the filtrate carbon; subjecting the biocharand filtrate carbon to a neutral atmosphere at or above temperatures of250° C. for a predetermined time interval to form inert carbon; andusing the inert carbon as coal. In some embodiments, this coal isequivalent to anthracite coal.

Other embodiments of the invention involve a method for carbonsequestration, comprising: providing biomass to a pyrolyzing system,wherein the pyrolyzing system generates biochar and filtrate carbon;collecting the biochar and the filtrate carbon; subjecting the biocharand filtrate carbon to a neutral atmosphere at or above temperatures of250° C. for a predetermined time interval; and using the biochar as acapture element for the filtrate carbon to form dense carbon aggregates.The method may further entail compressing the carbon aggregates intopellets.

Further embodiments of the invention involve a system for carbonsequestration, comprising: means for providing biomass to a pyrolyzingsystem, wherein the pyrolyzing system generates biochar and filtratecarbon; means for collecting the biochar and the filtrate carbon; meansfor subjecting the biochar and filtrate carbon to a neutral atmosphereat or above temperatures of 250° C. for a predetermined time interval toform inert carbon; and means for using the inert carbon as coal. In someembodiments, this coal is equivalent to anthracite coal.

Additional embodiments of the invention involve a system for carbonsequestration, comprising: means for providing biomass to a pyrolyzingsystem, wherein the pyrolyzing system generates biochar and filtratecarbon; means for collecting the biochar and the filtrate carbon; meansfor subjecting the biochar and filtrate carbon to a neutral atmosphereat or above temperatures of 250° C. for a predetermined time interval;and means for using the biochar as a capture element for the filtratecarbon to form dense carbon aggregates. The system may further entailmeans for compressing the carbon aggregates into pellets.

Other features and aspects of the invention will become apparent fromthe following detailed description, which discloses by way of example,the features in accordance with embodiments of the invention. Thesummary is not intended to limit the scope of the invention, which isdefined solely by the claims attached hereto.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

According to various embodiments of the invention, systems and methodsare provided to specifically address the atmospheric concentration ofCO₂ and either reduce or balance it against increased fossil fuel carbonemissions. Embodiments of the invention produce highly inert carbon viavarious pyrolysis products of biomass. More specifically, in accordancewith some embodiments of the invention, CO₂ is sequestered into forms ofcarbon known to be viable for long-term storage. For example, someembodiments sequester CO₂ into coal, which is a form of carbon that isideal for long-term carbon storage. Coal formations do not requiremassive amounts of another mineral or compound to facilitate storage.

Biomass input can be of any common type including wood, grasses, leaves,compost, food crop residues, wildfire abatement trimmings, and biomassfrom land use conversion. The biomass can be fed into any type ofpyrolyzing system ranging from a flash pyrolyzer, which operates on asub-second basis to roasting techniques that require several hours. Thepyrolysis process can be oxygen or air fed and, thus, rely on partialoxidation for heating, or, it can be indirectly heated and operate ininert or reducing atmospheres to minimize partial oxidation products.The pyrolyzer can operate in a vacuum, at atmospheric pressure, or athigh pressure. It can operate with a gaseous, liquid or supercriticalfluid working medium. In most cases, the carbon output from suchpyrolysis operations includes two or more components, typicallyincluding the following: (A) biochar which is small aggregates of carbonwhich partially retain some of the cellular structure of the originalbiomaterial and (B) micro to nanoscale filtrate carbon from thepyrolyzer's gas or liquid working medium

The biochar (A) is typically mechanically concentrated and discharged bygravity or pressure from an accumulation point inside the pyrolyzer.Such material can be ground or milled by common techniques convenientlyinto the 100-mesh size range.

Filtrate carbon (B) is ultra-fine carbon that typically forms from thedehydration and dehydrogenation of gasses and liquids which stream fromthe biomass during the pyrolysis process. Some of these particles can beextremely fine and are components of the persistent smoke, whichpermeates the atmosphere from large wildfires. These fine particles mustbe removed by one or more stages of fine filtration including, but notlimited to, centrifugal separation techniques such as cyclones, diskcentrifuges, compartmentalized centrifuges, etc. and mechanicalfiltration techniques such as mechanically wiped filters, reverseflushed filters, etc.

Within some embodiments, the biomass pyrolyzer can be operated for thesole purpose of making sequesterable carbon, while in others it can beoperated for multiple purposes. In yet other embodiments, the pyrolyzercan be operated largely for another commercial purpose with carboncapture as an auxiliary function. For example, other purposes for thepyrolyzer include the production of biofuels or chemical feedstock forfurther processing into fuels or industrial chemicals.

For some embodiments, in order for the pyrolyzer's output carbon to besuitable for long-term geologic storage as hard coal, it must be highlyinert and free of residual hydrogen and oxygen compounds or radicals,which could produce undesirable side reactions such as the long-termevolution of methane gas, etc. For example, if the atmosphere isreducing in nature, it could actually hydrogenate leftover surfaceradicals, which could lead to later stage undesirable reactions.Conversely, an oxidizing atmosphere will effectively clean radicals fromthe carbon surface, but it will tend to burn the substrate carbon tofowl CO2 and carbon monoxide, thus reducing the carbon yield from theprocess, therefore, a high temperature neutral atmosphere typicallyprovides the optimal yield of inert carbon. Accordingly, in order toachieve a high level of inertness, some embodiments use the pyrolyzer tooptimally subject both types of carbon particles to a neutral atmosphereat temperatures above 250° C. (and preferably 450° C.) for severalseconds to several minutes depending upon the rate of gas diffusionthrough the carbon particle stream. Other embodiments do so as anauxiliary or secondary process after pyrolyzation.

Typically, the ultimate results of the purification process will be aquantity of medium mesh, semi-porous biochar and a large quantity offiltrate carbon ranging in size from 400 mesh down to submicronnano-particles. These ultra-fine particles represent a particularchallenge in that when dry, they will very readily disperse in air as afine dark smoke, similar, but even more persistent than diesel smoke.These particles readily wet and can be locally controlled in water, butwater based transport is undesirable because it adds substantial mass tobe transported and any localized drying throughout the handling processproduces very fine carbon air dispersals.

Eventually, the biochar (A) and the filtrate carbon (B) can be mixedinto a water-based slurry and pressed into pellets. The porous nature ofthe biochar acts as a filtration matrix for the much finer filtratecarbon during wet pressing operations such that the water squeezed outof the press typically runs clear. For hardwood based pyrolysisproducts, and a 1″ diameter press die, the water removal is complete andcompaction is complete at about 5 tons per square inch press pressure.The resultant pellet, which can practically be a fraction of an inchtall to over an inch tall, can be directly handled in the semi-dry statewith minimum carbon shedding. However, once such a carbon pellet startsto dry, it internally cracks and starts to shed carbon such that after afew days on a lab bench, it becomes very mechanically unsound and willdisintegrate and produce a carbon dust plume with minimal handling. Aspressed, with a 10 ton per square inch peak pressure, these pellets havean apparent density of about 1.2 which is somewhat higher thanbituminous coal and in the lower range of anthracite coal. Elementalcarbon has a density of about 2, so both these pellets and natural coalshave significant residual porosity, which can be largely explained bythe interspatial void volume for densely packed hard spheres whichyields about 55% equivalent solid packing density.

In order to meaningfully impact atmospheric CO₂ levels, billions of tonsof carbon must be sequestered as coal per year. Assuming an effectivefield density of about 1, a billion tons of carbon, or a gigaton ofcarbon, commonly referred to in the environmental literature as one GTCrequires a volume one mile wide by one mile long by 1,100 feet thick, orone mile by eleven miles by 100 feet thick. Some long termenergy/population/atmospheric models would imply a total requirement tostore about 4 GTC per year worldwide, or roughly 1 GTC in the Americas,1 GTC in Europe, 1 GTC in Northern Asia and 1 GTC in Southern Asia.Since there are very few large geographic formations and the transportcost over long distances is very significant, it is much more likelythat these requirements would be met by dozens to hundreds of smallerstorage sites, initially including mining reclamation sites where carbonsequestration coal would be put back in place of removed coal or othermined minerals. In such cases, the coal strata would typically be 30 to50 feet in thickness and it would be highly desirable to minimize therequired amount of overburden coverage. Such rock, subsoil and topsoilcoverage would typically minimally be in the range of the same thicknessas the carbon deposit. It is therefore important that the carbonfeedstock to this storage process be conveniently transportable overmoderate distances using existing infrastructure such as railroads andthat it have minimal excess mass, i.e., minimal water content. Since, atan apparent density of 1.2, any added water will substantially increasethe transport weight. It is also important that the carbon be inert soas not to contaminate the local ecology and that it be densified to beload bearing in a stable geometry to provide a stable ground surfaceabove it. In order to accomplish all these transport and field beddinggoals, the carbon should be pelletized into a size that is suitable forthe transport and depositing equipment and for the geology andreclamation use of the storage site. Anthracite coal has been shippedfor over 100 years on railroads and already has a standard range ofpellet sizes that are in a suitable range for further consideration forthese carbon sequestration pellets. The standard small sizes foranthracite coal are as follows:

Classification Minimum Size (inches) Maximum Size (inches) Chestnut ⅞ 1-½ Pea 9/16 ⅞  Buckwheat ⅜  9/16 Rice 3/16 ⅜  Barley 3/32 3/16

In order to produce functional pellets, some embodiments add a bindingagent to the biochar plus filtrate carbon mix. Since this process willbe run in huge quantities, the binding agent must be readily available,preferably as a natural part of the pyrolysis process, non-toxic,non-polluting, biodegradable, water dispersible, and ultra-low cost.Simple plant starches appear to be an optimal candidate in that allplants store energy in starch grains and plant matter is the fundamentalfeedstock to the pyrolysis and carbon sequestration process. Simplestarches make up the predominant mass of corn, potatoes, food grains andplant tubers. In addition, food starch behavior has been utilized forthousands of years. Starch particles in plants are typically in themicron size range and are typically composed of microcrystallinestructures of the carbohydrates amylase and amylopectin. These starchgranules are not water soluble at room temperature, but are readilydispersed in water because of their small size. This starch binder canbe dispersed in water at about 1%40% concentration, heated to 100° C.for one minute with agitation to hydrolyze the starch into a gel andthen mixed one to one on a weight basis with biochar and filtratecarbon. For example, wood based pyrolysis carbons are mixed with a warmsolution of 5% cornstarch and pressed at 8 tons peak in a 1″ diametermold with thicknesses in the range of ½″ to 1″. About 70% of the starchis retained in the pellet, with the balance in the press water, whichcan be subsequently recycled to make more pellets with proportionallyless added starch. The pellet is then dried for 30 minutes at 240° C. ina standard laboratory-drying oven to remove the excess water andcrosslink the starch. The resulting pellet can be handled withoutshedding carbon and is dimensionally stable. This process results in theuse of about 70 pounds of starch per ton of carbon pellets or 19 poundsof starch per ton of sequestered CO₂. A freshly pressed pellet 0.5″thick ruptures at about 500 pounds loading in a lab compression test.The drying process must achieve pellet core temperatures high enough tocrosslink the starch, but not so high as to initiate auto-ignition ofthe carbon surface when operated in an open-air environment. If thepellets are heated in a neutral atmosphere, they can be dried andcrosslinked faster via higher peak temperatures without the danger ofigniting their surfaces. However, very high local temperatures willpyrolyzer the binder, causing it to lose its effectiveness. A neutralinert atmosphere for accelerated pellet drying can conveniently use CO₂and water vapor from a pyrolyzer or oxygen depleted recirculatingexhaust gas containing nitrogen, CO₂ and water vapor. Such recirculatingexhaust gas would typically be found in a pyrolyzing station's dieselpowered electric generator's exhaust system.

This type of self-filtering pelletizing process tends to concentratemore binder in the center of the pellets than at the surfaces so thatthe impact strength of the surface, which is important to minimizeflaking during transport and bedding is lower than the bulk strength ofthe pellet. The surface strength of the pellets and their impactresistance can be further improved by spraying a higher concentrationstarch solution, i.e., 6%-8% on the surfaces of the pellets near the endof the initial drying process and extending the drying process byanother 25%-50% to accommodate this surface treatment. The resultantsurface coated pellets can be very durable with respect to impacts fromone another and thus can simplify transport and bedding handling issuesat about a 20% increase in starch loading.

The secondary surface coating has an added benefit of reducing thesurface porosity and thus the water uptake of the pellets. Starch boundpellets can retain their strength and handling durability for longperiods if they are kept dry. Such a pellet can be submerged in water atroom temperature for one week and still retain its shape withoutshedding carbon, but at a highly reduced mechanical strength. Suchwater-induced degradation of the pellet structure may be highlydesirable in some bed compaction schemes, but it requires keeping thepellet dry until bedding.

Since, for some embodiments, these carbon pellets will be bedded intolarge coal strata formations in a wide range of climate conditions andunder all weather conditions including rainy seasons, freeze-thaw cyclesand permafrost strata, particular care with concern to the interactionof the pellets and local water during the bed compaction process isrequired. Freely dispersing carbon as released from an impropersequestration methodology could become analogous to some of the infamouslarge-scale sludge ponds that hold billions of gallons of coal miningtailings. Thus, in order to accommodate a wide range of storage sitehydrology, the option to substantially vary the submerged water behaviorof such pellets is expected to be required.

The water uptake of the pellets and their mechanical strength in watercan be greatly enhanced by adding a thin film coating of naturalbiodegradable water repellant. Pine rosin, which has been used as anatural water proofing agent for thousands of years (e.g. as wood boatcaulking agent), works particularly well in this application. Pine rosinis a natural resin made up mostly of abietic or sylvic acid. It is alsothe main ingredient in natural wood varnishes. The rosin can beharvested from pine trees or extracted from soft wood feedstock cominginto the pyrolyzers. For example, a 0.08 mil thick rosin coating on 1″thick, 1″ diameter pellets, as described above, requires about 1 poundof rosin per ton of carbon pellets or 1 pound of rosin for every 7,000pounds of sequestered CO₂. Rosin can be heated above its melting pointto about 150° C. and sprayed directly on the pellets at the end of theirdrying cycle. The resulting pellets are water repellant andsubstantially more durable than their corresponding anthracite coalanalogs. Given that common kitchen cling wrap is about 0.15 mil thick, amechanically rosin coating that is 0.08 mil thick is quite substantialsuch that, in some applications, thinner coatings could be utilized.

Since atmospheric carbon sequestration involves a huge quantity ofcarbon to be deposited in a large number of geographic areas fromdiverse feedstock, and is subject to a wide range of geological andclimatological considerations, a range of different pellet sizes andbinder and water proofing agent concentrations may be utilized withinthe general scope of this patent. Some of the basic considerations ofpellet design are volume versus surface area, water uptake andcontrolled degradability at the ultimate storage sites. In general,smaller pellets require less structural binder for transport because ofthe minimal impact forces that small structures are subjected to.However, small volume structures have proportionally larger surfaceareas so surface treatment costs increase as size gets smaller. Waterrepelling agents such as natural rosin are both expensive and canproduce too long of a biodecay cycle, that is, they could decaysubstantially after the initial bedding compaction, causing later stageground shifts, if not carefully engineered to the proper coatingthickness.

Natural coal deposits can be subject to coal fires that can be difficultto extinguish. To minimize the possibility of fire propagation and todiscourage the pirating of the carbon deposit for use as fuel, thepellets should be loosely packed with existing overburden. Additionally,for very thick storage deposits, walls of the natural ground stratashould be either left in place or re-deposited to folio storage chambersto minimize the possibility of any bulk ground movement due to mixingtogether two different densities of material with different compressivestrengths and water absorption rates. Each site will have to becarefully geologically and hydrologically engineered for properlong-term storage.

From time-to-time, the present invention is described herein in terms ofthese example environments. Description in terms of these environmentsis provided to allow the various features and embodiments of theinvention to be portrayed in the context of an exemplary application.After reading this description, it will become apparent to one ofordinary skill in the art how the invention can be implemented indifferent and alternative environments.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as is commonly understood by one of ordinary skillin the art to which this invention belongs. All patents, applications,published applications and other publications referred to herein areincorporated by reference in their entirety. If a definition set forthin this section is contrary to or otherwise inconsistent with adefinition set forth in applications, published applications and otherpublications that are herein incorporated by reference, the definitionset forth in this section prevails over the definition that isincorporated herein by reference.

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only, and not of limitation. Likewise, the various diagrams maydepict an example architectural or other configuration for theinvention, which is done to aid in understanding the features andfunctionality that can be included in the invention. The invention isnot restricted to the illustrated example architectures orconfigurations, but the desired features can be implemented using avariety of alternative architectures and configurations. Indeed, it willbe apparent to one of skill in the art how alternative functional,logical or physical partitioning and configurations can be implementedto implement the desired features of the present invention. Also, amultitude of different constituent module names other than thosedepicted herein can be applied to the various partitions. Additionally,with regard to flow diagrams, operational descriptions and methodclaims, the order in which the steps are presented herein shall notmandate that various embodiments be implemented to perform the recitedfunctionality in the same order unless the context dictates otherwise.

Although the invention is described above in terms of various exemplaryembodiments and implementations, it should be understood that thevarious features, aspects and functionality described in one or more ofthe individual embodiments are not limited in their applicability to theparticular embodiment with which they are described, but instead can beapplied, alone or in various combinations, to one or more of the otherembodiments of the invention, whether or not such embodiments aredescribed and whether or not such features are presented as being a partof a described embodiment. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the ten is “a”or “an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

A group of items linked with the conjunction “and” should not be read asrequiring that each and every one of those items be present in thegrouping, but rather should be read as “and/or” unless expressly statedotherwise. Similarly, a group of items linked with the conjunction “or”should not be read as requiring mutual exclusivity among that group, butrather should also be read as “and/or” unless expressly statedotherwise. Furthermore, although items, elements or components of theinvention may be described or claimed in the singular, the plural iscontemplated to be within the scope thereof unless limitation to thesingular is explicitly stated.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. The use of theterm “module” does not imply that the components or functionalitydescribed or claimed as part of the module are all configured in acommon package. Indeed, any or all of the various components of amodule, whether control logic or other components, can be combined in asingle package or separately maintained and can further be distributedin multiple groupings or packages or across multiple locations.

Additionally, the various embodiments set forth herein are described interms of exemplary block diagrams, flow charts and other illustrations.As will become apparent to one of ordinary skill in the art afterreading this document, the illustrated embodiments and their variousalternatives can be implemented without confinement to the illustratedexamples. For example, block diagrams and their accompanying descriptionshould not be construed as mandating a particular architecture orconfiguration.

1. A method for carbon sequestration, comprising: providing biomass to apyrolyzing system, wherein the pyrolyzing system generates biochar andfiltrate carbon; collecting the biochar and the filtrate carbon;subjecting the biochar and filtrate carbon to a neutral atmosphere at orabove temperatures of 250° C. for a predetermined time interval to forminert carbon; and using the inert carbon as coal.
 2. The method of claim1, wherein the coal is equivalent to anthracite coal.
 3. A method forcarbon sequestration, comprising: providing biomass to a pyrolyzingsystem, wherein the pyrolyzing system generates biochar and filtratecarbon; collecting the biochar and the filtrate carbon; subjecting thebiochar and filtrate carbon to a neutral atmosphere at or abovetemperatures of 250° C. for a predetermined time interval; and using thebiochar as a capture element for the filtrate carbon to form densecarbon aggregates.
 4. The method of claim 3, further comprisingcompressing the carbon aggregates into pellets.
 5. The method of claim4, wherein the carbon aggregates are compressed with a peak pressureranging approximately from 4,000 to 20,000 psi.
 6. The method of claim5, wherein the carbon aggregates are compressed with a water-basedstarch binder having a starch concentration ranging approximately from1% to 10%.
 7. The method of claim 6, further comprising drying andcrosslinking the starch binder in open air at a temperature rangingapproximately from 200° C. to 250° C. for approximately 30 minutes to 1hour.
 8. The method of claim 5, wherein the carbon aggregates arecompressed with a water-based starch binder having a starchconcentration of approximately 4%; and the method further comprising:drying and crosslinking the starch binder in open air at a temperatureranging approximately from 200° C. to 250° C. for approximately 45minutes to 1 hour and 30 minutes; and spraying a hot starch solutionwith a starch concentration of approximately 7% on to all surfaces ofthe pellet at the end of the drying.
 9. The method of claim 4, whereinthe carbon aggregates are compressed with a peak pressure ofapproximately 10,000 psi and with a water-based starch binder having astarch concentration ranging approximately from 1% to 10%; and thepellets that result are I″ in diameter and ½″ to 1″ thick.
 10. Themethod of claim 9, further comprising drying and crosslinking the starchbinder in open air at a temperature of approximately 230° C. forapproximately 30 minutes.
 11. The method of claim 9, further comprisingdrying and crosslinking the starch binder in open air at a temperatureof approximately 300° C. for approximately 15 minutes in an inertatmosphere of CO₂ nitrogen and water vapor, wherein the CO₂ and nitrogencomprises 70% or more vapor pressure.
 12. The method of claim 4, whereinthe carbon aggregates are compressed with a peak pressure ofapproximately 10,000 psi and with a water-based starch binder having astarch concentration of approximately 4%; and the method furthercomprising: drying and crosslinking the starch binder in open air at atemperature ranging approximately from 200° C. to 250° C. forapproximately 45 minutes to 1 hour 30 minutes; and spraying a hot starchsolution having a starch concentration of approximately 7% on to allsurfaces of each pellet at the end of the drying.
 13. The method ofclaim 4, wherein a secondary coat is applied to each pellet by sprayinga hot molten pine rosin on to all surfaces of the pellet at the end of astarch drying cycle such that a coating 0.02 mils to 0.08 mils thickresults.
 14. The method of claim 4, further comprising aweather-protected means for transporting the pellets to a long-termunderground storage location.
 15. The method of claim 14, wherein thelong-term underground storage location utilized is a reclaimed surfacemine.
 16. The method of claim 14, wherein the long-term undergroundstorage location comprises an underground storage facility in which thepellets are stored in layers ranging approximately from 10 to 50 feetdeep.
 17. The method of claim 16, wherein the pellets are tightlycompacted with an overburden material.
 18. The method of claim 17,wherein material originally removed to create the long-term undergroundstorage location is used as the overburden material.
 19. The method ofclaim 17, wherein the top layer material scraped away to create thelong-term underground storage location is used as the overburdenmaterial.
 20. The method of claim 17, wherein the overburden material isapproximately the same thickness as the underground storage facility'sstorage seam depth.
 21. The method of claim 16, wherein the undergroundstorage facility has a storage packing structure in which the pelletsare stored, wherein an inert fill material is placed between thepellets, thereby minimizing the potential propagation of undergroundcoal seam fires.
 22. The method of claim 16, wherein the undergroundstorage facility has a storage packing structure in which the pelletsare stored, wherein groups of the pellets are compartmentalized withsections of inert fill material, thereby minimizing the potentialpropagation of underground coal seam fires.
 23. The method of claim 16,wherein the pellets stored by the underground storage facility havecontrolled structural degradation based on water exposure, therebyallowing the pellets to be seamlessly compacted into the undergroundstorage facility.
 24. The method of claim 23, wherein the pellets aredesigned based on controlled degradation of the starch binder used indry storage environments, shallow strata, or with a large amount ofmix-in with the overburden material surrounding the pellets.
 25. Themethod of claim 23, wherein the pellets are coated with a durable waterrepellant rosin, thereby allowing construction of storage arrays in awet environment, a water submerged environment, or in an environmentthat is subject to expected water exposure prior to replacement by theunderground storage facility.
 26. A system for carbon sequestration,comprising: means for providing biomass to a pyrolyzing system, whereinthe pyrolyzing system generates biochar and filtrate carbon; means forcollecting the biochar and the filtrate carbon; means for subjecting thebiochar and filtrate carbon to a neutral atmosphere at or abovetemperatures of 250° C. for a predetermined time interval to form inertcarbon; and means for using the inert carbon as coal.
 27. The system ofclaim 26, wherein the coal is equivalent to anthracite coal.
 28. Asystem for carbon sequestration, comprising: means for providing biomassto a pyrolyzing system, wherein the pyrolyzing system generates biocharand filtrate carbon; means for collecting the biochar and the filtratecarbon; means for subjecting the biochar and filtrate carbon to aneutral atmosphere at or above temperatures of 250° C. for apredetermined time interval; and means for using the biochar as acapture element for the filtrate carbon to form dense carbon aggregates.29. The system of claim 28, further comprising means for compressing thecarbon aggregates into pellets.
 30. The system of claim 29, wherein thecarbon aggregates are compressed with a peak pressure rangingapproximately from 4,000 to 20,000 psi.
 31. The system of claim 30,wherein the carbon aggregates are compressed with a water-based starchbinder having a starch concentration ranging approximately from 1% to10%.
 32. The system of claim 31, further comprising means for drying andcrosslinking the starch binder in open air at a temperature rangingapproximately from 200° C. to 250° C. for approximately 30 minutes to 1hour.
 33. The system of claim 30, wherein the carbon aggregates arecompressed with a water-based starch binder having a starchconcentration of approximately 4%; and the system further comprising:means for drying and crosslinking the starch binder in open air at atemperature ranging approximately from 200° C. to 250° C. forapproximately 45 minutes to 1 hour and 30 minutes; and means forspraying a hot starch solution with a starch concentration ofapproximately 7% on to all surfaces of the pellet at the end of thedrying.
 34. The system of claim 29, wherein the carbon aggregates arecompressed with a peak pressure of approximately 10,000 psi and with awater-based starch binder having a starch concentration rangingapproximately from 1% to 10%; and the pellets that result are 1″ indiameter and ½″ to 1″ thick.
 35. The system of claim 34, furthercomprising means for drying and crosslinking the starch binder in openair at a temperature of approximately 230° C. for approximately 30minutes.
 36. The system of claim 34, further comprising means for dryingand crosslinking the starch binder in open air at a temperature ofapproximately 300° C. for approximately 15 minutes in an inertatmosphere of CO₂ nitrogen and water vapor, wherein the CO₂ and nitrogencomprises 70% or more vapor pressure.
 37. The system of claim 4, whereinthe carbon aggregates are compressed with a peak pressure ofapproximately 10,000 psi and with a water-based starch binder having astarch concentration of approximately 4%; and the system furthercomprising: means for drying and crosslinking the starch binder in openair at a temperature ranging approximately from 200° C. to 250° C. forapproximately 45 minutes to 1 hour 30 minutes; and means for spraying ahot starch solution having a starch concentration of approximately 7% onto all surfaces of each pellet at the end of the drying.
 38. The systemof claim 29, wherein a secondary coat is applied to each pellet byspraying a hot molten pine rosin on to all surfaces of the pellet at theend of a starch drying cycle such that a coating 0.02 mils to 0.08 milsthick results.
 39. The system of claim 29, further comprising aweather-protected means for transporting the pellets to a long-termunderground storage location.
 40. The system of claim 39, wherein thelong-term underground storage location utilized is a reclaimed surfacemine.
 41. The system of claim 39, wherein the long-term undergroundstorage location comprises an underground storage facility in which thepellets are stored in layers ranging approximately from 10 to 50 feetdeep.
 42. The system of claim 41, wherein the pellets are tightlycompacted with an overburden material.
 43. The system of claim 42,wherein material originally removed to create the long-term undergroundstorage location is used as the overburden material.
 44. The system ofclaim 42, wherein the top layer material scraped away to create thelong-term underground storage location is used as the overburdenmaterial.
 45. The system of claim 42, wherein the overburden material isapproximately the same thickness as the underground storage facility'sstorage seam depth.
 46. The system of claim 41, wherein the undergroundstorage facility has a storage packing structure in which the pelletsare stored, wherein an inert fill material is placed between thepellets, thereby minimizing the potential propagation of undergroundcoal seam fires.
 47. The system of claim 41, wherein the undergroundstorage facility has a storage packing structure in which the pelletsare stored, wherein groups of the pellets are compartmentalized withsections of inert fill material, thereby minimizing the potentialpropagation of underground coal seam fires.
 48. The system of claim 41,wherein the pellets stored by the underground storage facility havecontrolled structural degradation based on water exposure, therebyallowing the pellets to be seamlessly compacted into the undergroundstorage facility.
 49. The system of claim 48, wherein the pellets aredesigned based on controlled degradation of the starch binder used indry storage environments, shallow strata, or with a large amount ofmix-in with the overburden material surrounding the pellets.
 50. Thesystem of claim 48, wherein the pellets are coated with a durable waterrepellant rosin, thereby allowing construction of storage arrays in awet environment, a water submerged environment, or in an environmentthat is subject to expected water exposure prior to replacement by theunderground storage facility.